Tensioners are well known devices to apply a constant belt-tensioning force that compensates for increases in belt length due to wear.
Such tensioners generally provide a fixed structure, mounted on a fixed support such as a motor vehicle, and a pivot structure eccentrically mounted on the fixed structure by means of a pivot assembly. The pivot assembly may provide bearing. The pivot structure further provides a pulley structure onto which the belt is engaged.
Such tensioners further provide elastic means, such as a coil spring, that is mounted between the fixed and the pivot structures. The elastic means exert a biasing force between the structures so as to adjust a constant belt tension.
It is known from EP 1 412 659 B1 to provide a temporary coupling structure to be received by the tensioner. The coupling structure permits a temporary coupling between the pivot structure and an eccentric adjusting member on which the pivot structure is mounted for eccentric pivoting movement.
When installing a tensioner according to EP 1 412 659 B1, the eccentric adjusting member and the pivot structure are coupled in rotation in a direction against the biasing force exerted by the biasing member. The belt is then mounted on the tensioner. The eccentric adjusting member and the pivot structure are then coupled in rotation in an opposite direction so that the biasing member is relieved. The eccentric adjusting member and the pivot structure are decoupled. The eccentric adjusting member is then pivoting so as to adjust the belt tension to a predetermined value and is finally tightened onto the support. When the tensioner is installed, the eccentric adjusting member forms the tensioner fixed structure.
However, the tensioner requires a dedicated coupling member that must be installed in a specific position, with the pivot structure and the eccentric adjusting member in a specific relative position.
Each tensioner must be provided with such a coupling member that is thrown away after installation.